According to the CDC, measles is transmitted when an infected person coughs or sneezes; infected people are contagious from four days before their rash starts through four days afterwards.

After an infected person leaves a location, the virus remains alive for up to two hours on surfaces and in the air. The incubation period—the period from exposure to onset of symptoms—is typically 10-14 days, but can be as long as 21 days, according to the CDC.

State epidemiologist Siiri Bennett says the Maine CDC is working with clinicians to identify potentially exposed individuals.

The public may have been exposed to measles if they were at the following locations between June 15 and 19:

Individuals who were potentially exposed should review their vaccine history and monitor for symptoms. Individuals with symptoms should contact their providers for instructions before arriving at the providers’ offices or hospitals.

Measles is a vaccine-preventable disease that can cause pneumonia and death.